Relay unit and air conditioning apparatus

ABSTRACT

A relay unit connected to one or a plurality of outdoor units and a plurality of indoor units by different pipeline systems, respectively, so as to exchange heat between a refrigerant circulating through the outdoor unit and a heat medium different from the refrigerant and to circulate the heat medium through the indoor unit, provided with a valve block unit in which a plurality of valve blocks integrated with at least a plurality of branch pipes connected to the indoor unit, a plurality of main pipes which become channels for the heat medium relating to the heat exchange, and heat medium flow direction switching devices that switch the main pipes to communicate with the branch pipes are connected.

TECHNICAL FIELD

The present invention relates to a relay unit and an air conditioning apparatus. The present invention particularly relates to simplification of a pipeline structure, size reduction of equipment, improvement of serviceability, and the like in the relay unit.

BACKGROUND ART

Hitherto, a multiple air conditioning apparatus for a building to which an air conditioning apparatus that performs a cooling operation or a heating operation by circulating a refrigerant between an outdoor unit, which is a heat source machine arranged outside a room, and an indoor unit arranged inside the room so as to convey cold or heat to a region to be air-conditioned such as indoors and the like is applied has been present (See Patent Literature 1, for example). As the refrigerant used in such an air conditioning apparatus, HFC refrigerants, for example, are widely used. Also, a natural refrigerant such as carbon dioxide (CO₂) and the like has begun to be used.

Also, an air conditioning apparatus of another configuration represented by a chiller system is used. In this air conditioning apparatus, cold or heat is generated in a heat source machine arranged outside the room, the cold or heat is transferred to a heat medium such as water, an anti-freezing fluid and the like by a heat exchanger arranged in the outdoor unit, and the heat medium is conveyed to a fan coil unit, a panel heater and the like, which is an indoor unit arranged in a region to be air-conditioned, so as to perform the cooling operation or heating operation (See Patent Literature 2, for example). Moreover, there is known a waste heat recovery type chiller in which four water pipelines are connected to a heat source machine so as to supply cold or heat.

CITATION LIST Patent Literature

-   PTL 1: Japanese Unexamined Patent Application Publication No.     2-118372 (page 3, FIG. 1) -   PTL 2: Japanese Unexamined Patent Application Publication No.     2003-343936 (page 5, FIG. 1)

SUMMARY OF INVENTION Technical Problem

With a prior-art air conditioning apparatus, since a high-pressure refrigerant is conveyed to an indoor unit, a refrigerant charged amount becomes extremely large, and if the refrigerant leaks from a refrigerant circuit, harmful effects to the global environment such as deterioration of global warming may occur. Particularly, R410A has as large global warming potential of 1970, and if such a refrigerant is to be used, reduction of the refrigerant charged amount becomes extremely important from the viewpoint of global environmental protection. Also, if the refrigerant leaks into a living space, chemical properties of the refrigerant might affect the human body. Thus, measures such as more ventilation than necessary, installation of a leakage sensor, and the like are required, which lead to increases in costs and power consumption.

Such a problem can be solved by the chiller system as described in Patent Literature 2. However, since heat is exchanged performed between the refrigerant and water in the outdoor unit and the water is conveyed to the indoor unit, water conveying power becomes extremely large, and energy consumption is increased. Also, if both cold and heat are to be supplied by water or the like, the number of connected pipelines needs to be increased, which results in an increase in labor, time and costs required for installation work. Thus, to simplify the pipeline construction on the site, if a connection pipeline, valves, and a heat exchanger are contained on the device side in advance, the devices contained in the pipeline or valves become extremely large, which results in a cost increase and lowered productivity.

Thus, there is known a device in which a relay unit that exchanges heat between the refrigerant and water and the like is provided between the outdoor unit and the indoor unit so that the water conveying power does not become large. Here, the relay unit does not directly act on air conditioning of a target space, and in view of leakage of the refrigerant and the like, it is expected that the relay unit is connected by a pipeline to an indoor unit on each floor and installed in a space with many restrictions such as in the attic. Therefore, the pipeline structure is preferably simplified and made small. Particularly in the size reduction, making a thinner structure is preferable so that the relay unit can cope with an environment with harsh restrictions in one direction such as the height direction. However, the relay unit might handle cooling and heating energy at the same time, and if a pipeline handling the cooling energy is located close to the pipeline handling the heating energy through mere size-reduction, energy efficiency is deteriorated, and thus, measures are needed. Also, considering installation in a restricted space, consideration should be given so that maintenance and the like can be performed easily, for example.

The present invention was made in order to solve the above problems and an object thereof is to provide an air conditioning apparatus and the like which can be made thinner and allow for easy maintenance and time reduction while saving energy.

Solution to Problem

A relay unit according to the present invention is connected to one or a plurality of outdoor units and a plurality of indoor units by different pipeline systems, respectively, so as to exchange heat between a refrigerant circulating through the outdoor unit and a heat medium different from the refrigerant and to circulate the heat medium through the indoor unit, provided with a valve block unit to which a plurality of valve blocks integrated with at least a plurality of branch pipes connected to the indoor unit, a plurality of main pipes which become channels for the heat medium relating to the heat exchange, and a heat medium flow direction switching device that switches the main pipes to communicate with the branch pipe are connected.

Advantageous Effects of Invention

In the relay unit according to the present invention, since the valve block unit to which the plurality of valve blocks integrated with the plurality of branch pipes, the plurality of main pipes, and the heat medium flow direction switching device are connected, the pipeline can be simplified, the relay unit can be made thinner, and installation can be made effectively even in an environment with harsh restrictions such as in the attic.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an outline circuit diagram illustrating a configuration of an air conditioning apparatus on which a valve block unit according to Embodiment 1 is mounted.

FIG. 2 is a refrigerant circuit diagram illustrating a flow of a refrigerant in a cooling-main operation mode of the air conditioning apparatus.

FIG. 3 is a refrigerant circuit diagram illustrating an outline configuration of the valve block unit in the air conditioning apparatus.

FIG. 4 is a perspective view illustrating the structure of the valve block unit in detail.

FIG. 4 a is an exploded perspective view illustrating a state in which the valve block unit is exploded.

FIG. 4 b is a view of the valve block unit when seen from a side face.

FIG. 5 is a longitudinal sectional view illustrating a sectional configuration of a valve block in a simplified manner.

FIG. 6 is an explanatory diagram for explaining a valve body.

FIG. 7 is an explanatory diagram for explaining a valve body.

FIG. 8 is an outline diagram illustrating a rotating state of the valve body.

FIG. 9 is an explanatory diagram for explaining connection of the valve block.

FIG. 10 is an explanatory diagram for explaining connection of the valve block.

FIG. 11 a is a graph illustrating an example of a relationship between a pipeline distance and a temperature rise.

FIG. 11 b is a graph illustrating an example of the relationship between the pipeline distance and the temperature rise.

FIG. 11 c is a graph illustrating an example of the relationship between the pipeline distance and the temperature rise.

FIG. 12 is an explanatory diagram for explaining another means that suppresses thermal interference.

FIG. 13 is a view illustrating an appearance of a relay unit 3 according to Embodiment 2.

FIG. 14 is a view illustrating the connection of a valve block unit 300.

FIG. 15 is a diagram illustrating an outline of a structure of a housing 600 that contains the relay unit 3.

FIG. 16 is a diagram illustrating a relationship between the valve block unit 300 and a heat medium heat exchanger 15.

FIG. 17 is a diagram illustrating another example of an installed form of the relay unit 3.

FIG. 18 is a longitudinal sectional view illustrating a sectional configuration of the valve block constituting the valve block unit according to Embodiment 4 in a simplified manner.

FIG. 19 is an explanatory diagram for explaining the valve body.

FIG. 20 is a perspective view illustrating the structure of the valve block unit in detail.

FIG. 21 is an explanatory diagram for explaining the connection of the valve block.

FIG. 22 is an explanatory diagram for explaining the connection of the valve block.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below.

Embodiment 1

FIG. 1 is an outline circuit diagram illustrating a configuration of an air conditioning apparatus 100 on which a valve block unit 300 according to Embodiment 1 of the present invention is mounted. On the basis of FIG. 1, a detailed configuration of the air conditioning apparatus 100 will be described. As shown in FIG. 1, an outdoor unit 1 and a relay unit 3 are connected through a first heat medium heat exchanger 15 a and a second heat medium heat exchanger 15 b and the relay unit 3 and an indoor unit 2 are connected through the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b. Configurations and functions of each constituent device disposed in the air conditioning apparatus 100 will be described below.

[Outdoor Unit 1]

In the outdoor unit 1, a compressor 10, a four-way valve 11, which is a refrigerant flow direction switching device, a heat-source side heat exchanger 12, and an accumulator 17 are connected and contained in series by a refrigerant pipeline 4. Also, in the outdoor unit 1, a first connection pipeline 4 a, a second connection pipeline 4 b, a check valve 13 a, a check valve 13 b, a check valve 13 c, and a check valve 13 d are disposed. By disposing the first connection pipeline 4 a, the second connection pipeline 4 b, the check valve 13 a, the check valve 13 b, the check valve 13 c, and the check valve 13 d, the flow direction of the heat-source-side refrigerant made to flow into the relay unit 3 can be made constant regardless of an operation required by the indoor unit 2.

The compressor 10 is to suck in the heat-source-side refrigerant and to compress the heat-source-side refrigerant to bring it into a high-temperature high-pressure state and is preferably composed of an inverter compressor or the like capable of capacity control, for example. The four-way valve 11 is to perform switching between the flow of the heat-source-side refrigerant during a heating operation and the flow of the heat-source-side refrigerant during the cooling operation. The heat-source-side heat exchanger 12 functions as an evaporator during the heating operation, while it functions as a condenser during the cooling operation so as to exchange heat between the air supplied from a blower such as a fan, not shown, and the heat-source-side refrigerant and to evaporate and gasify the heat-source-side refrigerant or to condense and liquefy the same. The accumulator 17 is disposed in the suction side of the compressor 10 and stores an excess refrigerant.

The check valve 13 d is disposed in the refrigerant pipeline 4 between the relay unit 3 and the four-way valve 11 so as to allow the flow of the heat-source-side refrigerant only in a predetermined direction (direction from the relay unit 3 to the outdoor unit 1). The check valve 13 a is disposed in the refrigerant pipeline 4 between the heat-source side heat exchanger 12 and the relay unit 3 so as to allow the flow of the heat-source-side refrigerant only in a predetermined direction (direction from the outdoor unit 1 to the relay unit 3). The check valve 13 b is disposed in the first connection pipeline 4 a so as to allow the flow of the heat-source-side refrigerant only in the direction from the upstream side of the check valve 13 d to the upstream side of the check valve 13 a. The check valve 13 c is disposed in the second connection pipeline 4 b so as to allow the flow of the heat-source-side refrigerant only in the direction from the downstream side of the check valve 13 d to the downstream side of the check valve 13 a.

The first connection pipeline 4 a connects the refrigerant pipeline 4 on the upstream side of the check valve 13 d and the refrigerant pipeline 4 on the upstream side of the check valve 13 a to each other in the outdoor unit 1. The second connection pipeline 4 b connects the refrigerant pipeline 4 on the downstream side of the check valve 13 d and the refrigerant pipeline 4 on the downstream side of the check valve 13 a to each other in the outdoor unit 1. In FIG. 1, the example in which the first connection pipeline 4 a, the second connection pipeline 4 b, the check valve 13 a, the check valve 13 b, the check valve 13 c, and the check valve 13 d are disposed is shown, but that example is not limiting, and they do not necessarily have to be disposed.

[Indoor Unit 2]

On the indoor units 2, use-side heat exchangers 26 are mounted, respectively. This use-side heat exchanger 26 is connected to a heat medium flow control device 24 and a heat medium flow direction switching device 23 of the relay unit 3 through the pipeline 5. This use-side heat exchanger 26 exchanges heat between the air supplied from the blower such as a fan, not shown, and a heat medium and generates air for heating or air for cooling to be supplied to a region to be air-conditioned.

In FIG. 1, the example in which four indoor units 2 are connected to the relay unit 3 is shown, in which an indoor unit 2 a, an indoor unit 2 b, an indoor unit 2 c, and an indoor unit 2 d from the lower side in the figure are shown. Corresponding to the indoor units 2 a to 2 d, the use-side heat exchanger 26 is also shown from the lower side in the figure as a use-side heat exchanger 26 a, a use-side heat exchanger 26 b, a use-side heat exchanger 26 c, and a use-side heat exchanger 26 d. The number of connected indoor units 2 is not limited to four units shown in FIG. 1.

[Relay Unit 3]

The relay unit 3 is composed of a gas-liquid separator 14, a expansion device 16 e, two heat medium heat exchangers 15 (the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b), four expansion devices 16, two heat medium delivery devices 21, four heat medium flow direction switching devices 22, four heat medium flow direction switching devices 23, and four heat medium flow control devices 24 are disposed.

The gas-liquid separator 14 is connected to the single refrigerant pipeline 4 connected to the outdoor unit 1 and the two refrigerant pipelines 4 connected to the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b so as to separate the heat-source-side refrigerant supplied from the outdoor unit 1 to a vapor-state refrigerant and a liquid refrigerant. The expansion device 16 e is disposed between the refrigerant pipeline 4 that connects the expansion device 16 a and the expansion device 16 b to each other and the gas-liquid separator 14 and functions as a decompression valve or an expansion device so as to decompress and expand the heat-source-side refrigerant. The expansion device 16 e is preferably composed of a valve with variably controllable opening degree such as an electronic expansion valve, for example.

The two heat medium heat exchangers 15 (the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b) function as condensers or evaporators, exchange heat between the heat-source-side refrigerant and the heat medium and supply cold or heat generated in the outdoor unit 1 to the indoor units 2. In the flow of the heat-source-side refrigerant, the first heat medium heat exchanger 15 a is disposed between the gas-liquid separator 14 and the expansion device 16 d. In the flow of the heat-source-side refrigerant, the second heat medium heat exchanger 15 b is disposed between the expansion device 16 a and the expansion device 16 c.

The four expansion devices 16 (the expansion devices 16 a to 16 d) function as decompression valves or expansion valves and decompress and expand the heat-source-side refrigerant. The expansion device 16 a is disposed between the expansion device 16 a and the second heat medium heat exchanger 15 b. The expansion device 16 b is disposed in parallel with the expansion device 16 a. The expansion device 16 c is disposed between the second heat exchanger 15 b and the outdoor unit 1. The expansion device 16 d is disposed between the first heat exchanger 15 a and the expansion device 16 a as well as the expansion device 16 b. The four expansion devices 16 are preferably composed of devices with variably controllable opening degree such as electronic expansion valve, for example.

The two heat medium delivery devices 21 (the first heat medium delivery device 21 a and the second heat medium delivery device 21 b) are composed of pumps and the like and pressurize and circulate the heat medium guided through the pipeline 5. The first heat medium delivery device 21 a is disposed in the pipeline 5 between the first heat medium heat exchanger 15 a and the heat medium flow direction switching device 22. The second heat medium delivery device 21 b is disposed in the pipeline 5 between the second heat medium heat exchanger 15 b and the heat medium flow direction switching device 22. The types of the first heat medium delivery device 21 a and the second heat medium delivery device 21 b are not particularly limited but may be configured by a capacity-controllable pump or the like.

The four heat medium flow direction switching devices 22 (the heat medium flow direction switching devices 22 a to 22 d) are composed of three-way valves and switch the channels of the heat medium. The heat medium flow direction switching devices 22 are disposed in the number (four, here) according to the number of the installed indoor units 2. As for the heat medium flow direction switching devices 22, one of the three ways is connected to the first heat medium heat exchanger 15 a, another one of the three ways to the second heat medium heat exchanger 15, and the rest of the three ways to the heat medium flow control device 24, respectively, and they are disposed on the inlet side of a heat medium channel of the use-side heat exchanger 26. Corresponding to the indoor units 2, they are shown as the heat medium flow direction switching device 22 a, the heat medium flow direction switching device 22 b, the heat medium flow direction switching device 22 c, and the heat medium flow direction switching device 22 d from the lower side in the figure.

The four heat medium flow direction switching devices 23 (the heat medium flow direction switching devices 23 a to 23 d) are composed of three-way valves and switch the channels of the heat medium. The heat medium flow direction switching devices 23 are disposed in the number (four, here) according to the number of the installed indoor units 2. As for the heat medium flow direction switching devices 23, one of the three ways is connected to the first heat medium heat exchanger 15 a, another one of the three ways to the second heat medium heat exchanger 15 b, and the rest of the three ways to the use-side heat exchanger 26, respectively, and they are disposed on the outlet side of a heat medium channel of the use-side heat exchanger 26. Corresponding to the indoor units 2, they are shown as the heat medium flow direction switching valve 23 a, the c heat medium flow direction switching valve 23 b, the heat medium flow direction switching valve 23 c, and the heat medium flow direction switching valve 23 d from the lower side in the figure.

The four heat medium flow control devices 24 (the heat medium flow control devices 24 a to 24 d) are composed of two-way valves and switch the channel of the heat medium. The heat medium flow control devices 24 are disposed in the number (four, here) according to the number of the installed indoor units 2. One side of each of the heat medium flow control devices 24 is connected to the use side heat exchanger 26, while the other side is connected to the heat medium flow direction switching device 22, and they are disposed on the inlet side of the heat medium channel of the use-side heat exchanger 26. Corresponding to the indoor units 2, they are shown as the heat medium flow control device 24 a, the heat medium flow control device 24 b, the heat medium flow control device 24 c, and the heat medium flow control device 24 d from the lower side in the figure.

Also, in the relay unit 3, two first heat medium temperature detecting means 31, two second heat medium temperature detecting means 32, four third heat medium temperature detecting means 33, four fourth heat medium temperature detecting means 34, a first refrigerant temperature detecting means 35, a refrigerant pressure detecting means 36, a second refrigerant temperature detecting means 37, and a third refrigerant temperature detecting means 38 are disposed. Information detected by these detecting means is sent to a controller, not shown, that controls the operation of the air conditioning apparatus 100 and used for control of driving frequencies of the compressor 10 and the heat medium delivery device 21, switching of the channel for the heat medium flowing through the pipeline 5 and the like.

The two first heat medium temperature detecting means 31 (a first heat medium temperature detecting means 31 a and a first heat medium temperature detecting means 31 b) detect the temperature of the heat medium flowing out of the heat medium heat exchanger 15, that is, the heat medium temperature at the outlet of the heat medium heat exchanger 15 and are preferably composed of thermistors or the like. The first heat medium temperature detecting means 31 a is disposed in the pipeline 5 on the inlet side of the first heat medium delivery device 21 a. The second heat medium temperature detecting means 31 b is disposed in the pipeline 5 on the inlet side of the second heat medium delivery device 21 b.

The two second heat medium temperature detecting means 32 (a second heat medium temperature detecting means 32 a and a second heat medium temperature detecting means 32 b) detect the temperature of the heat medium flowing into the heat medium heat exchanger 15, that is, the heat medium temperature at the inlet of the heat medium heat exchanger 15 and are preferably composed of thermistors or the like. The second heat medium temperature detecting means 32 a is disposed in the pipeline 5 on the inlet side of the first heat medium heat exchanger 15 a. The second heat medium temperature detecting means 32 b is disposed in the pipeline 5 on the inlet side of the second heat medium heat exchanger 15 b.

The four third heat medium temperature detecting means 33 (third heat medium temperature detecting means 33 a to 33 d) are disposed on the inlet side of the heat medium channel of the use-side heat exchanger 26 and detect the temperature of the heat medium flowing into the use-side heat exchanger 26, and the detecting means is preferably composed of a thermistor or the like. The third heat medium temperature detecting means 33 are disposed in number (four, here) according to the installed number of the indoor units 2. Corresponding to the indoor units 2, they are shown as the third heat medium temperature detecting means 33 a, the third heat medium temperature detecting means 33 b, the third heat medium temperature detecting means 33 c, and the third heat medium temperature detecting means 33 d from the lower side in the figure.

The four fourth heat medium temperature detecting means 34 (fourth heat medium temperature detecting means 34 a to 34 d) are disposed on the outlet side of the heat medium channel of the use-side heat exchanger 26 and detect the temperature of the heat medium flowing out of the use-side heat exchanger 26, and the detecting means is preferably composed of a thermistor or the like. The fourth heat medium temperature detecting means 34 are disposed in number (four, here) according to the installed number of the indoor units 2. Corresponding to the indoor units 2, they are shown as the fourth heat medium temperature detecting means 34 a, the fourth heat medium temperature detecting means 34 b, the fourth heat medium temperature detecting means 34 c, and the fourth heat medium temperature detecting means 34 d from the lower side in the figure.

The first refrigerant temperature detecting means 35 is disposed at the outlet side of the heat-source-side refrigerant channel of the first heat medium heat exchanger 15 a and detects the temperature of the heat-source-side refrigerant flowing out of the first heat medium heat exchanger 15 a, and the detecting means is preferably composed of a thermistor or the like. The refrigerant pressure detecting means 36 is disposed on the outlet side of the heat-source-side refrigerant channel of the first heat medium heat exchanger 15 a and detects a pressure of the heat-source-side refrigerant flowing out of the first heat medium heat exchanger 15 a and can be constituted by a pressure sensor or the like.

The second refrigerant temperature detecting means 37 is disposed on the inlet side of the heat-source-side refrigerant channel of the second heat medium heat exchanger 15 b and detects the temperature of the heat-source-side refrigerant flowing into the second heat medium heat exchanger 15 b, and the detecting means is preferably composed of a thermistor or the like. The third refrigerant temperature detecting means 38 is disposed on the outlet side of the heat-source-side refrigerant channel of the second heat medium heat exchanger 15 b and detects a temperature of the heat-source-side refrigerant flowing out of the second heat medium heat exchanger 15 b, and the detecting means is preferably composed of a thermistor or the like.

The pipeline 5 through which the heat medium is guided is composed of a pipeline connected to the first heat medium heat exchanger 15 a (hereinafter referred to as a pipeline 5 a) and a pipeline connected to the second heat medium heat exchanger 15 b (hereinafter referred to as, a pipeline 5 b). The pipeline 5 a and the pipeline 5 b are branched in accordance with the number (here, branched to four each) of the indoor units 2 connected to the relay unit 3. And the pipeline 5 a and the pipeline 5 b are connected by the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23. By controlling the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23, it is determined whether the heat medium guided through the pipeline 5 a is made to flow into the use-side heat exchanger 26 or the heat medium guided through the pipeline 5 b is made to flow into the use-side heat exchanger 26.

In this air conditioning apparatus 100, the compressor 10, the four-way valve 11, the heat-source side heat exchanger 12, the first heat medium heat exchanger 15 a, and the second heat medium heat exchanger 15 b are connected by the refrigerant pipeline 4 in series in the order so as to constitute a refrigeration cycle. Also, the first heat medium heat exchanger 15 a, the first heat medium delivery device 21 a, and the use-side heat exchanger 26 are connected by the pipeline 5 a in series in the order so as to constitute a heat medium circulation circuit. Similarly, the second heat medium heat exchanger 15 b, the second heat medium delivery device 21 b, and the use-side heat exchanger 26 are connected by the pipeline 5 b in series in the order so as to constitute a heat medium circulation circuit. That is, a plurality of use-side heat exchangers 26 are connected in parallel with each of the heat medium heat exchangers 15 so as to form plural systems of the heat medium circulation circuits.

That is, the outdoor unit 1 and the relay unit 3 are connected to each other through the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b disposed in the relay unit 3. And the relay unit 3 and the indoor units 2 are connected by the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b so that the heat-source-side refrigerant, which is the primary-side refrigerant which circulates through the refrigeration cycle in the first heat medium heat exchanger 15 a and the second heat medium heat exchanger 15 b, exchange heat with the heat medium, which is the secondary-side refrigerant which circulates through the heat medium circulation circuit.

Here, the type of the refrigerant used in the refrigeration cycle and the heat medium circulation circuit will be described.

For the refrigeration cycle, a nonazeotropic refrigerant mixture such as R407c, a near-azeotropic refrigerant mixture such as R410A, a single refrigerant such as R22 and the like can be used. Also, a natural refrigerant such as carbon dioxide, hydrocarbon and the like may be used. By using the natural refrigerant as the heat-source-side refrigerant, an advantage that a global warming effect caused by leakage of the refrigerant can be suppressed is obtained.

The heat medium-circulation circuit is connected to the use-side heat exchanger 26 of the indoor unit 2 as described above. Thus, in the air conditioning apparatus 100, considering the case of leakage of the heat medium into a room where the indoor unit 2 is installed or the like, use of the heat medium with high safety is premised. Therefore, for the heat medium, water, an anti-freezing solution, a mixed liquid of water and the anti-freezing solution and the like can be used, for example. According to this configuration, refrigerant leakage caused by freezing or corrosion can be prevented even at a low outside temperature, and high reliability can be obtained. Also, if the indoor unit 2 is installed in a place where moisture should be avoided such as a computer room, a fluorine inactive liquid with high heat insulation can be used as the heat medium.

This air conditioning apparatus 100 is, on the basis of an instruction from each indoor unit 2, capable of the cooling operation or the heating operation with the indoor unit 2 thereof. That is, the air conditioning apparatus 100 is capable of performing the same operation with all the indoor units 2 or of performing different operations with each of the indoor units 2. There are four operation modes executed by the air conditioning apparatus 100 include a cooling-only operation mode in which all the driving indoor units 2 perform the cooling operation, a heating-only operation mode in which all the driving indoor units 2 perform the heating operation, a cooling-main operation mode in which a cooling load is larger, and a heating-main operation mode in which a heating load is larger. In each of the operation modes, the cooling-main operation mode in which the cooling and the heating are mixed and the cooling load shares the most will be described.

[Cooling-Main Operation Mode]

FIG. 2 is a refrigerant circuit diagram illustrating the flow of the refrigerant during the cooling-main operation mode of the air conditioning apparatus 100. In FIG. 2, using an example in which a heating load is generated in the use-side heat exchanger 26 a and a cooling load is generated in the use-side heat exchangers 26 b to 26 d, the cooling-main operation mode will be described. In FIG. 2, the pipeline expressed by a bold line indicates a pipeline through which the refrigerant (heat-source-side refrigerant and heat medium) circulates. Also, the flow direction of the heat-source-side refrigerant is indicated by a solid-line arrow, while the flow direction of the heat medium by a broken-line arrow.

First, the flow of the heat-source-side refrigerant in the refrigeration cycle will be described.

The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature high-pressure gas refrigerant. The high-temperature high-pressure gas refrigerant discharged from the compressor 10 passes through the four-way valve 11 and flows into the heat-source side heat exchanger 12. Then, the refrigerant is condensed while radiating heat to the outdoor air in the heat-source side heat exchanger 12 and becomes a gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant having flowed out of the heat-source side heat exchanger 12 flows out of the outdoor unit 1 via the check valve 13 a and flows into the relay unit 3 via the refrigerant pipeline 4. The gas-liquid two-phase refrigerant having flowed into the relay unit 3 flows into the gas-liquid separator 14 and is separated to a gas refrigerant and a liquid refrigerant.

The gas refrigerant having been separated in the gas-liquid separator 14 flows into the first heat medium heat exchanger 15 a. The gas refrigerant having flowed into the first heat medium heat exchanger 15 a is condensed and liquefied while radiating heat to the heat medium circulating through the heat medium circulation circuit and becomes a liquid refrigerant. The liquid refrigerant having flowed out of the first heat medium heat exchanger 15 a passes through the expansion device 16 d. On the other hand, the liquid refrigerant separated in the gas-liquid separator 14 passes through the expansion device 16 e, is condensed and liquefied in the first heat medium heat exchanger 15 a but merges with the liquid refrigerant having passed through the expansion device 16 d, is throttled by the expansion device 16 a and expanded and flows into the second heat medium heat exchanger 15 b as the low-temperature and low-pressure gas-liquid two-phase refrigerant.

This gas-liquid two-phase refrigerant absorbs heat from the heat medium circulating through the heat medium circulation circuit in the second heat medium heat exchanger 15 b working as an evaporator so as to cool the heat medium and becomes a low-temperature and low-pressure gas refrigerant. The gas refrigerant having flowed out of the second heat medium heat exchanger 15 b passes through the expansion device 16 c and then, flows out of the relay unit 3 and flows into the outdoor unit 1 via the refrigerant pipeline 4. The refrigerant having flowed into the outdoor unit 1 passes through the check valve 13 d and is sucked into the compressor 10 again via the four-way valve 11 and the accumulator 17. The expansion device 16 b has a small opening degree so that the refrigerant does not flow therethrough, and the expansion device 16 c is in the full open state so that a pressure loss does not occur.

Subsequently, the flow of the heat medium in the heat medium circulation circuit will be described.

The heat medium having been pressurized by the first heat medium delivery device 21 a and flowed out passes through the heat medium flow control device 24 a via the heat medium flow direction switching device 22 a and flows into the use-side heat exchanger 26 a. Then, in the use-side heat exchanger 26 a, the heat medium gives heat to the indoor air and performs heating of the region to be air-conditioned such as the inside of the room where the indoor unit 2 is installed. Also, the heat medium having been pressurized by the second heat medium delivery device 21 b and flowed out passes through the heat medium flow control devices 24 b to 24 d via the heat medium flow direction switching devices 22 b to 22 d and flows into the use-side heat exchangers 26 b to 26 d. Then, in the use-side heat exchangers 26 b to 26 d, the heat medium absorbs heat from the indoor air and performs cooling of the region to be air-conditioned such as the inside of the room where the indoor unit 2 is installed.

The heat medium used for the heating operation flows into the use-side heat exchanger 26 a only in a flow rate required to cover the air-conditioning load required in the region to be air-conditioned by means of an action of the heat medium flow control device 24 a. Then, the heat medium having performed the heating operation flows into the first heat medium heat exchanger 15 a via the heat medium flow direction switching device 23 a and is sucked into the first heat medium delivery device 21 a again.

The heat medium used for the cooling operation flows into the use-side heat exchangers 26 b to 26 d only in a flow rate required to cover the air-conditioning load required in the region to be air-conditioned by means of an action of the heat medium flow control devices 24 b to 24 d. Then, the heat medium having performed the cooling operation flows into the second heat medium heat exchanger 15 b via the heat medium flow direction switching device 23 b and is sucked into the second heat medium delivery device 21 b again.

FIG. 3 is a refrigerant circuit diagram illustrating an outline configuration of a valve block unit 300 in the air conditioning apparatus 100. On the basis of FIG. 3, the configuration of the valve block unit 300 will be described. In Embodiment 1, a portion surrounded by a broken line in FIG. 3 is made into a block and constituted as the valve block unit 300. As is known from FIG. 3, the valve block unit 300 is composed of the heat medium flow direction switching device 22, the heat medium flow direction switching device 23, the heat medium flow control device 24, a cooling outward-flow main pipe 307, a heating outward-flow main pipe 308, a cooling return-flow main pipe 305, a heating return-flow main pipe 306, a first branch pipe 301, and a second branch pipe 302.

Each of the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, the heating return-flow main pipe 306, the first branch pipe 301, and the second branch pipe 302 constitutes a part of the above-described pipeline 5. Also, the first branch pipe 301 constitutes a channel that guides the heat medium to the load side (indoor unit 2), and the second branch pipe 302 constitutes a channel through which the heat medium returns from the load side (indoor unit). The first branch pipe 301 and the second branch pipe 302 will be described in detail in FIG. 5.

The heat medium flow direction switching device 22 and the heat medium flow direction switching device 23 correspond to at least one flow direction switching means having a valve body. The cooling outward-flow main pipe 307 corresponds to a first pipeline through which guiding of the heat medium is selectively switched by the heat medium flow direction switching device 22. The heating outward-flow main pipe 308 corresponds to a second pipeline through which guiding of the heat medium is selectively switched by the heat medium flow direction switching device 22. The cooling return-flow main pipe 305 corresponds to the first pipeline through which guiding of the heat medium is selectively switched by the heat medium flow direction switching device 23. The heating return-flow main pipe 306 corresponds to the second pipeline through which guiding of the heat medium is selectively switched by the heat medium flow direction switching device 23.

That is the valve block unit 300 according to Embodiment 1 is constituted by four valve blocks, in which one set is composed of the heat medium flow direction switching device 22, the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, and the branch pipe 301 and another set is composed of the heat medium flow direction switching device 23, the cooling return-flow main pipe 305, the heating return-flow main pipe 306, and the branch pipe 302 are formed, are connected. In FIG. 3, a state in which the heat medium flow control device 24 is disposed in the valve block unit 300 is illustrated as an example, but the heat medium flow control device 24 is not indispensable or may be disposed on the branch pipe 302 side.

This valve block unit 300 is preferably formed by a material with small heat conductivity (a metal material or a plastic material) as a main material since hot water and cold water flow through the inside, thermal interference occurs, which incurs performance deterioration. The metal material includes stainless, brass, bronze, aluminum and the like. The plastic material includes PPS (polyphenylenesulfide), PPE (polyphenyleneether), cross-linked polyethylene or polybutene and the like, for example. In order to reduce the weight of the valve block unit 300, the plastic material is used as a main material further preferably.

FIG. 4 is a perspective view illustrating the structure of the valve block unit 300 in detail. On the basis of FIG. 4, the configuration of the valve block unit 300 will be described in more detail. The valve block unit 300 shown in FIG. 4 has four valve blocks 350 (valve block 350 a to valve block 350 d) connected as shown in FIG. 3, which are connected to the four indoor units 2. The valve block 350 has the heat medium flow direction switching device 22, the heat medium flow direction switching device 23, and the heat medium flow control device 24, which covers one branch portion. That is, the valve block unit 300 according to the Embodiment 1 has four branches.

FIG. 4 a is an exploded perspective view illustrating a state in which the valve block unit 300 is exploded. On the basis of FIG. 4 a, assembling of the valve block unit 300 branching into four parts will be described. As described above, the valve block unit 300 is formed by the valve block 350 a, the valve block 350 b, the valve block 350 c, and the valve block 350 d connected to each other.

Then, the cooling outward-flow main pipe 307 (illustrated as a cooling outward-flow main pipe 307 a, a cooling outward-flow main pipe 307 b, a cooling outward-flow main pipe 307 c, and a cooling outward-flow main pipe 307 d from the right side in the figure), the heating outward-flow main pipe 308 (illustrated as a heating outward-flow main pipe 308 a, a heating outward-flow main pipe 308 b, a heating outward-flow main pipe 308 c, and a heating outward-flow main pipe 308 d from the right side in the figure), the cooling return-flow main pipe 305 (illustrated as a cooling return-flow main pipe 305 a, a cooling return-flow main pipe 305 b, a cooling return-flow main pipe 305 c, and a cooling return-flow main pipe 305 d from the right side in the figure), and the heating return-flow main pipe 306 (illustrated as a heating return-flow main pipe 306 a, a heating return-flow main pipe 306 b, a heating return-flow main pipe 306 c, and a heating return-flow main pipe 306 d from the right side in the figure) of each valve block 350 are connected to each other, respectively, so as to form the main pipe (pipeline 5).

One end of each main pipe (the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306) is formed into a female shape and the other end is formed into a male shape capable of connecting to the female-shaped end so that the valve blocks 350 can be connected. And on the cooling outward-flow main pipe 307 a and the heating outward-flow main pipe 308 a of the valve block 350 a located at one of the both ends of the valve block unit 300, caps 318 that cap them are disposed. On the other hand, on the cooling return-flow main pipe 305 d and the heating return-flow main pipe 306 d of the valve block 350 d located at the other of the both ends of the valve block unit 300, caps 319 that cap them are disposed.

The cap 318 and the cap 319 are used for two main pipes of the four main pipes. That is, in the valve block 350 a, the cooling outward-flow main pipe 307 a and the heating outward-flow main pipe 308 a are capped with the caps 318, while the cooling return-flow main pipe 305 a and the heating return-flow main pipe 306 a are not capped with the caps 319. The heating return-flow main pipe 306 a is connected to the suction side of the heating-side pump (first heat medium delivery device 21 a) and the cooling return-flow main pipe 305 a is connected to the suction side of the cooling side pump (second heat medium delivery device 21 b), respectively.

On the other hand, in the valve block 350 d, the cooling return-flow main pipe 305 d and the heating return-flow main pipe 306 d are capped with the caps 319, while the cooling outward-flow main pipe 307 d and the heating outward-flow main pipe 308 d are not capped with the caps 318. The heating outward-flow main pipe 308 d is connected to the discharge side of the heating-side pump and the cooling outward-flow main pipe 307 d is connected to the discharge side of the cooling side pump, respectively. The cap 318 and the cap 319 have shapes corresponding to the shape of the end of each pipeline. As shown in FIG. 4 a, the cap 318 has a shape according to the male pipeline end (a lid shape so as to cover the pipeline end) and the cap 319 has a shape according to the female pipeline end (a plug shape to be fitted in the pipeline).

On the other hand, in the valve block 350 d, the cooling return-flow main pipe 305 d and the heating return-flow main pipe 306 d are capped with the caps 319, while the cooling outward-flow main pipe 307 d and the heating outward-flow main pipe 308 d are not capped with the caps 318. The heating outward-flow main pipe 308 d is connected to the discharge side of the heating-side pump and the cooling outward-flow main pipe 307 d is connected to the discharge side of the cooling side pump, respectively. The cap 318 and the cap 319 have shapes corresponding to the shape of the end of each pipeline. As shown in FIG. 4 a, the cap 318 has a shape according to the male pipeline end (a lid shape so as to cover the pipeline end). As shown in FIG. 4 b, a lug is disposed on the cap end so that it can be fixed with a screw and screwed into the valve block main body. The cap 319 has a shape according to the female pipeline end and is fixed by a screw head as shown in FIG. 4 b.

As is known from this FIG. 4 a, the valve block unit 300 is capable of switching the heat medium flow direction and forms each main pipe by connecting a plurality of valve blocks 350. According to this valve block unit 300, pipelines around the valve can be simplified as compared with a device in which the flow direction switching device and the pipeline are provided separately. Therefore, the unit on which the valve block unit 300 is mounted (the relay unit 3 in Embodiment 1) can be made compact. A sacrificed hole 321 shown in FIG. 4 a is a hole required for forming the channel of the valve block 350. Since the sacrificed hole 321 needs to be independent among the valve blocks 350, it is shut off by a joint 320 in FIG. 4 a.

FIG. 5 is a longitudinal sectional view illustrating a sectional configuration of the valve block 350 in a simplified manner. On the basis of FIG. 5, the configuration of the valve block 350 constituting the valve block unit 300 will be described along with the flow of the heat medium. The first branch pipe 301 corresponds to a third pipeline that selectively communicates with the cooling outward-flow main pipe 307 or the heating outward-flow main pipe 308. That is, the first branch pipe 301 communicates with the cooling outward-flow main pipe 307 or the heating outward-flow main pipe 308 selectively switched by the heat medium flow direction switching device 22. The second branch pipe 302 corresponds to the third pipeline that selectively communicates with the cooling return-flow main pipe 305 or the heating return-flow main pipe 306. That is, the second branch pipe 302 communicates with the cooling return-flow main pipe 305 or the heating return-flow main pipe 306 selectively switched by the heat medium flow direction switching device 23. That is, the second branch pipe 302 communicates with the cooling return-flow main pipe 305 or the heating return-flow main pipe 306 selectively switched by the heat medium flow direction switching device 23.

Here, as shown in FIG. 5, the temperature detecting means 33 and the temperature detecting means 34 are incorporated in the pipeline. The temperature detecting means 33 is incorporated in the channel in the block. For the branch pipes 301 and 302, a copper pipe is used, and if the valve block 350 is made of plastic, the branch pipes 301 and 302 are brazed and connected to an extension pipeline during an installation work. At this time, since it is likely that the plastic of the valve block 350 is melted by heat conduction, the brazing is performed in a state in which the branch pipes 301 and 302 are removed from the valve block 350. In the case of fixation on the surface of the pipeline as in the prior-art temperature detecting means, the temperature detecting means is likely to be removed during brazing, and re-installation of the temperature detecting means might be forgotten when the work is completed. Thus, reliability of the device is lowered. Then, as shown in FIG. 5, by embedding the temperature detecting means 33 and 34 in the pipeline or in the channel, the risk of removal of the temperature detecting means can be eliminated, and reliability of the device is improved.

As is known from FIG. 4 a, the valve block unit 300 is capable of switching the heat medium channel and also forms each main pipe by connecting the plurality of valve blocks 350. According to this valve block unit 300, as compared with the device in which the flow direction switching device and the pipeline are provided separately, the pipeline around the valve can be simplified. Therefore, the unit on which the valve block unit 300 is mounted (the relay unit 3 in Embodiment 1) can be made compact.

FIG. 5 is a longitudinal sectional view illustrating a sectional configuration of the valve block 350 in a simplified manner. On the basis of FIG. 5, the configuration of the valve block 350 constituting the valve block unit 300 will be described along with the flow of the heat medium. The first branch pipe 301 corresponds to the third pipeline that selectively communicates with the cooling outward-flow main pipe 307 or the heating outward-flow main pipe 308. That is, the first branch pipe 301 communicates with the cooling outward-flow main pipe 307 or the heating outward-flow main pipe 308 selectively switched by the heat medium flow direction switching device 22. The second branch pipe 302 corresponds to the third pipeline that selectively communicates with the cooling return-flow main pipe 305 or the heating return-flow main pipe 306. That is, the second branch pipe 302 communicates with the cooling return-flow main pipe 305 or the heating return-flow main pipe 306 selectively switched by the heat medium flow direction switching device 23.

As described above, in each valve block, the heat medium flow direction switching device 22, the heat medium flow direction switching device 23, and the heat medium flow control device 24 are disposed. The heat medium flow direction switching device 22 is constituted by a valve body rotating means 310, a valve body 304 a, and a valve rod 313 that connects them. The valve body rotating means 310 is to rotate the valve body 304 a around a rotary shaft, not shown. The rotation of the valve body rotating means 310 is transmitted to the valve body 304 a via the valve rod 313.

The heat medium flow direction switching device 23 is constituted by a valve body rotating means 309, a valve body 304 b, and a valve rod 312 that connects them. The valve body rotating means 309 is to rotate the valve body 304 b around a rotary shaft, not shown. The rotation of the valve body rotating means 309 is transferred to the valve body 304 b via the valve rod 312. The heat medium flow control device 24 is constituted by a valve body rotating means 311, a valve body 303, and a valve rod 314 that connects them. The valve body rotating means 311 is to rotate the valve body 303 around a rotary shaft, not shown. The rotation of the valve body rotating means 311 is transferred to the valve body 303 via the valve rod 314.

As the valve body rotating means 309, the valve body rotating means 310, and the valve body rotating means 311, they can be driven by using a stepping motor and giving a pulse signal by control means, not shown, for example. Instead of the stepping motor, the valve body rotating means 309, the valve body rotating means 310, and the valve body rotating means 311 may be constituted by other motors such as a geared motor or the like. Also, the valve body 304 a and the valve body 304 b will be described in detail in FIG. 6 and the valve body 303 in FIG. 7, respectively.

The valve body 304 a, which is the sending side of the heat medium flow direction switching device 22, is disposed in a connection portion between the first branch pipe 301 and the cooling outward-flow main pipe 307 as well as the heating outward-flow main pipe 308. Similarly, the valve body 304 b, which is the sending side of the heat medium flow direction switching device 23, is disposed in a connection portion between the second branch pipe 302 and the cooling return-flow main pipe 305 or the heating return-flow main pipe 306. That is, the valve body 304 a and the valve body 304 b is rotated so as to communicate with the cooling-main pipe (a broken line arrow shown in FIG. 5) or the heating-main pipe (a solid line arrow shown in FIG. 5) and to switch between the cooling and the heating. If the valve body 303 of the heat medium flow control device 24 is rotated, an opening area is changed, and a flow rate of the heat medium to be sent into the indoor unit 2 can be adjusted.

FIG. 6 is an explanatory diagram for explaining the valve body 304 (the valve body 304 a and the valve body 304 b). On the basis of FIG. 6, the valve body 304 will be described in detail. FIG. 6 a is a perspective view of the valve body 304, FIG. 6 b is a plan view of the valve body 304, FIG. 6 c is a front view of the valve body 304 (side view seen from the side of an opening portion formed surface), FIG. 6 d is a left sectional view of the valve body 304, and FIG. 6 e is a bottom view of the valve body 304, respectively. In FIG. 6, the valve rod 312 is also illustrated (the same applies to the valve rod 313). In FIG. 6, the longitudinal direction of the valve body 304 is illustrated vertically, but in actuality, the valve body 304 is arranged so that the longitudinal direction thereof is laid horizontally, as shown in FIG. 5.

The valve body 304 is formed in a columnar shape. In this valve body 304, an opening portion 304 aa having an oval shape (a shape when the opening portion 304 aa is seen on a front view) is formed. When this opening portion 304 aa is seen on a side view, it has a tapered shape whose diameter is reduced toward the center axis direction of the valve body 304. The inside of the valve body 304 at a position where the opening portion 304 aa is formed is hollow, and a channel 304 ab communicating with the opening portion 304 aa is formed.

That is, in a state in which the opening portion 304 aa of the valve body 304 a is oriented downward (lower side in the state arranged as in FIG. 5), the first branch pipe 301 communicates with the cooling outward-flow main pipe 307. In a state in which the opening portion 304 aa is oriented to the cooling outward-flow main pipe 307 side, the heat medium passes through the opening portion 304 aa, passes through the inside of the valve body 304 a, passes through the channel 304 ab and is fed into the indoor unit 2 (a broken-line arrow shown in FIG. 5). On the other hand, in a state in which the opening portion 304 aa of the valve body 304 a is oriented upward (upper side in the state arranged as in FIG. 5), the first branch pipe 301 communicates with the heating outward-flow main pipe 308. In a state in which the opening portion 304 aa is oriented to the heating outward-flow main pipe 308 side, the heat medium passes through the opening portion 304 aa, passes through the inside of the valve body 304 a, passes through the channel 304 ab and is fed into the indoor unit 2 (a solid-line arrow shown in FIG. 5).

Similarly, in a state in which an opening portion 304 aa of the valve body 304 b is oriented downward (lower side in the state arranged as in FIG. 5), the second branch pipe 302 communicates with the cooling return-flow main pipe 305. In a state in which the opening portion 304 aa is oriented to the cooling return-flow main pipe 305 side, the heat medium passes through the channel 304 ab, passes through the inside of the valve body 304 b, passes through the opening portion 304 aa and flows into the cooling return-flow main pipe 305 (a broken-line arrow shown in FIG. 5). On the other hand, in a state in which an opening portion 304 aa of the valve body 304 b is oriented upward (upper side in the state arranged as in FIG. 5), the second branch pipe 302 communicates with the heating return-flow main pipe 306. In a state in which the opening portion 304 aa is oriented to the heating return-flow main pipe 306 side, the heat medium passes through the channel 304 ab, passes through the inside of the valve body 304 b, passes through the opening portion 304 aa and flows into the heating return-flow main pipe 306 (a broken-line arrow shown in FIG. 5).

FIG. 7 is an explanatory diagram for explaining the valve body 303. FIG. 8 is an outline diagram illustrating a rotating state of the valve body 303. On the basis of FIGS. 7 and 8, the valve body 303 will be described in detail. FIG. 7 a is a perspective view of the valve body 303, FIG. 7 b is a plan view of the valve body 303, FIG. 7 c is a front view of the valve body 303 (side view seen from the side of an opening portion formed surface), FIG. 7 d is left sectional view of the valve body 303, and FIG. 7 e is a bottom view of the valve body 303. In FIG. 7, the valve rod 314 is also illustrated. In FIG. 7, the longitudinal direction of the valve body 303 is illustrated vertically, but in actuality, the valve body 303 is arranged so that the longitudinal direction thereof is laid horizontally, as shown in FIG. 5.

The valve body 303 is a valve body of the heat medium flow control device 24 that adjusts the flow rate of the heat medium flowing into the indoor unit 2. This valve body 303 is constituted similarly to the valve body 304 described in FIG. 6. That is, the valve body 303 is formed in a columnar shape, an opening portion 303 a having an oval shape (a shape when the opening portion 303 a is seen on a front view) is formed, the inside of the valve body 303 at a position where the opening portion 303 a is formed is hollow, and a channel 303 b communicating with the opening portion 303 a is formed.

An operation of the heat medium flow control device 24 will be described in brief. On the basis of the information obtained from the third heat medium temperature detecting means 33 and the fourth heat medium temperature detecting means 34, the controller, not shown, calculates a required opening degree and transmits a required pulse number to the valve body rotating means 311. The valve body rotating means 311 rotates only by the received required pulse number and rotates the valve body 303. As shown in FIG. 8, by the rotation of the valve body 303, the opening area of the opening portion 303 a can be adjusted, and as a result, the flow rate of the heat medium can be adjusted. That is, by adjusting the opening area of the opening portion 303 a (a full-open state in FIG. 8A, a half-open state in FIG. 8B or an opening degree smaller than the half-open in FIG. 8C or the like), the flow rate of the heat medium flowing through the first branch pipe 301 can be variably adjusted.

As described above, the cooling outward-flow main pipe 307 and the heating return-flow main pipe 306 are arranged at adjacent positions (positions adjacent horizontally (in the right and left direction) at the substantially same height). Thus, the height of the valve block 350 (the length in the vertical direction in the state arranged as in FIG. 5) can be lowered. Also, since the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306 are incorporated in the one valve block 350, the valve block 350 can be made compact as compared with the device in which the main pipes are provided separately.

In the case of the cooling-only operation or the heating-only operation, the full amount of the heat medium flows through the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306, and the diameter of the main pipe (pipeline 5) constituted by them needs to be made larger. For example, in the cooling-only operation or the heating-only operation if water is used for the heat medium in the capacity of approximately 10 horse power, water at the rate of 85 liters/min. flows. If water is used as the medium, from the view point of prevention of inlet attack, the flow velocity is kept to 2.0 [m/s] or less. By setting the thickness of the pipeline to 1.0 [mm], a pipeline having a pipeline diameter of approximately 32 [mm] needs to be selected. If such a thick pipeline is to be bent or worked, there are many restrictions such that the bending R cannot be made small and a considerable space is required, and thus, the device becomes considerably large. On the other hand, in the valve block 350 according to this embodiment, four main pipeline constituting portions and the valve body 304 are disposed in the one valve block 350, and the plurality of valve blocks 350 are connected so that the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306 are automatically formed, the pipelines around the valve are simplified, and drastic size reduction can be realized. Also, in order to facilitate connection of the valve block 350, the connection portions are formed in the male and female shapes, and a seal is formed by an O-ring. As a result, manufacturing time is drastically reduced, and productivity is improved.

Also, by installing the valve body 303, the valve body 304 a, and the valve body 304 b such that the longitudinal directions thereof are not vertical (perpendicular direction) but horizontal, the first branch pipe 301 and the second branch pipe 302 to the indoor unit 2 can be also made lateral pipelines, and the height of the valve block 350 (the length in the vertical direction in the state arranged as in FIG. 5) can be further reduced. Moreover, by installing the valve body rotating means 309, the valve body rotating means 310, and the valve body rotating means 311 horizontally, the thickness of the valve block 350 can be drastically reduced (reduction in the length in the vertical direction in the state arranged as in FIG. 5). Since the relay unit 3 on which the valve block unit 300 is mounted is contained in a small place such as in the attic in many cases, the reduction in the height direction, that is, making a thinner structure is an important factor.

FIGS. 9 and 10 are explanatory diagrams for explaining connection of the valve block 350. On the basis of FIGS. 9 and 10, the connection of the valve block 350 will be described in detail. FIG. 9 a shows a side view of the valve block 350 and FIG. 9 b shows a B-B sectional view of FIG. 9 a in a state in which the valve block 350 is to be connected, respectively. Also, FIG. 10 shows a perspective view of a state in which the valve block 350 is to be connected. As described above, one end of each main pipe (the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306) is formed in the female shape and the other end in the male shape capable of being connected to the female-shaped end.

The end portion of the heating outward-flow main pipe 308 on the side face A side (left side in the figure) of the valve block 350 is a male-shaped connection portion. Around the end portion of this heating outward-flow main pipe 308, seal means 316 is mounted so that the valve block can be connected to another valve block 350. Also, the end portion of the cooling outward-flow main pipe 307 on the side face B side (right side in the figure) of the valve block 350 is a female-shaped connection portion. As the seal means 316, an O-ring or the like is preferably used. Also, other seal materials such as flat packing may be used for the seal means 316.

By employing the above structure, as shown in FIGS. 9 and 10, the plurality of valve blocks 350 can be connected easily, and the number of branches can be flexibly changed. Also, since the valve blocks 350 are constructed so as to be easily connected, workability (productivity) of the valve block 350 is also improved, and cost reduction can be realized. In FIGS. 9 and 10, the cooling outward-flow main pipe 307 and the heating outward-flow main pipe 308 are described as an example, but the same applies to the cooling return-flow main pipe 305 and the heating return-flow main pipe 306.

If the distance between the pipelines 5 on the cooling side (cooling outward-flow main pipe 307 and the cooling return-flow main pipe 305) and the pipelines 5 on the heating side (heating outward-flow main pipe 308 and the heating return-flow main pipe 306) is short, thermal interference might occur. If thermal interference occurs, the temperature of the heat medium flowing through the pipeline 5 on the cooling side is raised, and to the contrary, the temperature of the heat medium flowing through the pipeline 5 on the heating side is lowered, which might lead to performance deterioration. Thus, it is important to examine the distance between the pipeline 5 on the cooling side and the pipeline 5 on the heating side and the temperature change caused by that (See FIG. 13).

FIG. 11 a is a graph illustrating an example of a relationship between the pipeline distance and the temperature rise. On the basis of FIG. 11 a, the relationship of the distance between the pipeline 5 on the cooling side and the pipeline 5 on the heating side to the temperature change caused by that will be described. In FIG. 11 a, the horizontal axis indicates the pipeline distance [m] and the vertical axis indicates the temperature rise [° C.], respectively. In FIG. 11 a, a calculation result is shown as an example, assuming that the temperature of hot water (the temperature of the heat medium flowing through the main pipe on the heating side) is 45° C., the temperature of cold water (the temperature of the heat medium flowing through the main pipe on the cooling side) is 10° C., the pipeline material is polybutene, and the heat conductivity is 0.20 (W/mK). The pipeline diameter is 38 [mm] and the contact distance is 1 [mm].

From FIG. 11 a, it is known that the temperature change is saturated when the distance is approximately 15 mm (1.5 cm). From this result, it is known that the thermal interference can be suppressed by ensuring 15 mm or more for the distance between the main pipe on the cooling side and the main pipe on the heating side. Since the heat conductivity is different depending on the pipeline material, the relationship between the temperature rise and the pipeline distance is preferably examined for each heat conductivity. Thus, the examination result when the brass is used for the body material is shown in FIG. 11 b.

From FIG. 11 a, it is known that if the pipeline material is brass, the temperature change is saturated when the distance is approximately 100 mm. From this result, it is known that the thermal interference can be suppressed by ensuring 100 mm or more for the distance between the main pipe on the cooling side and the main pipe on the heating side. By ensuring 100 [mm] or more for the distance between the main pipe on the cooling side and the main pipe on the heating side, the thermal interference can be prevented, but the valve body block becomes extremely large, and the merit of size reduction by the valve-block unit is reduced. That is, if the material with large heat conductivity such as brass, copper, iron, aluminum and the like is used as the body material of the valve block, the main pipe on the cooling side needs to be thermally shut off from the main pipe on the heating side.

FIG. 12 is an explanatory diagram for explaining another means that suppresses thermal interference if prevention of the thermal interference is difficult with the above-described distance. On the basis of FIG. 12, another means that suppresses thermal interference between the pipeline 5 on the cooling side and the pipeline 5 on the heating side will be described. In FIG. 11 a and FIG. 11 b, the example in which the thermal interference is suppressed by the pipeline distance was described, but in FIG. 12, an example in which the thermal interference is suppressed by forming a slit 355 between the pipeline 5 on the cooling side and the pipeline 5 on the heating side so as to reduce an influence of heat conductivity is illustrated. As shown in FIG. 12, the thermal interference can be also suppressed by forming the slit 355. The thermal interference may be suppressed both by the pipeline distance and the slit.

In order to reduce the size of the valve-block unit, an upper limit of the distance between the main pipe on the cooling side and the main pipe on the heating side is considered to be approximately 20 [mm], and the heat conductivity at that time is approximately 1.0 [W/mK]. FIG. 11 c shows a relationship of the distance between the main pipe on the cooling side and the main pipe on the heating side to the temperature rise at 1.0 [W/mK]. As is known from FIG. 11 c, it is saturated approximately around 20 [mm]. The heat conductivity of cross-linked polyethylene is approximately 0.4 [W/mK], and the distance between the cooling-main pipe and the heating-main pipe required for saturation of the temperature rise is approximately 15 mm. Also, the heat conductivity of PPS is approximately 0.22 [W/mK], and thermal interference can be prevented by ensuring the same distance (15 mm) as that for polybutene.

In Embodiment 1, the example in which a near-azeotropic refrigerant such as R410A and R404A and the like, a nonazeotropic refrigerant mixture such as R407c and the like, a refrigerant having a relatively small global warming potential such as CF₃CF═CH₂ and the like including a double bond in the chemical formula or a mixture thereof or a natural refrigerant such as carbon dioxide, propane and the like can be used as the heat-source-side refrigerant as described above is described, but the refrigerant is not limited by those cited above. Also, in Embodiment 1, the example in which the accumulator 17 is disposed in the outdoor unit 1 is described, but without the accumulator 17, the same operation is performed and the same advantages are exerted.

Also, in general, an air blowing device is disposed in the heat-source-side heat exchanger 12 and the use-side heat exchanger 26 so that condensation or evaporation is promoted by air-blowing in many cases, but that example is not limiting. For example, as the use-side heat exchanger 26, a heat exchanger such as a panel heater using radiation can be used, and as the heat-source-side heat exchanger 12, a heat exchanger of a water-cooling type in which heat is moved by water or anti-freezing fluid can be used, and any type of heat exchanger can be used as long as its structure is capable of heat radiation or heat absorption.

The example in which the heat medium flow direction switching device 22, the heat medium c flow direction switching device 23, and the heat medium flow control device 24 are disposed corresponding to each of the use-side heat exchangers 26 is described, but that example is not limiting. For example, a plurality of them may be connected to one unit of the use-side heat exchanger 26. In this case, the heat medium flow direction switching device 22, the heat medium flow direction switching device 23, and the heat medium flow control device 24 connected to the same use-side heat exchanger 26 may be operated in the same way. Also, the example in which two units of the heat medium heat exchanger 15 are disposed is described, but naturally the number is not limiting, but three or more of them may be disposed as long as it is configured so that the heat medium can be cooled and/or heated.

Moreover, the example in which the third heat medium temperature detecting means 33 and the fourth heat medium temperature detecting means 34 are arranged inside the relay unit 3 is illustrated, but some of or all of them may be arranged inside the indoor unit 2. If they are arranged in the relay unit 3, the valves and pumps on the heat medium side and the like can be concentrated in the same housing, which leads to an advantage of easy maintenance. On the other hand, if they are arranged inside the indoor unit 2, they can be handled easily as in the case of the expansion valve in a prior-art direct expansion type indoor unit, and since it is installed close to the use-side heat exchanger 26, there is an advantage that it is not affected by heat loss of the extended pipeline and controllability of a heat load in the indoor unit 2 is good. Also, in a system to which a plurality of the indoor units 2 are connected, even if the heat medium flow control device 24 fails in one indoor unit 2, 22 can be replaced relatively easily without stopping the other indoor units 2.

As described above, since the valve block unit 300 according to Embodiment 1 is constituted by connecting the plurality of valve blocks 350, drastic size reduction can be realized. That is, the size reduction of the relay unit 3 on which the valve block unit 300 is mounted can be realized. Also, since the valve block 350 can be easily connected, assembling performance is improved, and labor or time required for installation can be reduced. Moreover, since the valve block unit 300 suppresses thermal interference of the pipelines 5, performance deterioration can be reduced. Therefore, by using the valve block unit 300, contribution can be made to energy saving.

Embodiment 2

FIG. 13 is a view illustrating an arrangement structure of the relay unit 3. The relay unit 3 in FIG. 13 has the valve block unit 300 formed by connecting 8 units of the valve blocks 350, and the heat medium can be made to branch into 8 units of the indoor units 2, respectively. By connecting the valve blocks 350 described in the above-described embodiment, the device and the pipeline that branch and merge the heat medium in each indoor unit 2 can be integrated and simplified, and moreover, by devising pipeline positions and the like, the relay unit 3 is thinned. Also, 8 units of the heat medium delivery devices 21 are provided. The 8 units of the heat medium delivery devices 21 are used in four each, respectively, for circulating the heat medium heated by the first heat medium heat exchanger 15 a and the heat medium cooled by the second heat medium heat exchanger 15 b, for example.

Here, the relay unit 3 in FIG. 13 has 8 units of the valve blocks 350 and 8 units of the heat medium delivery devices 21, but the numbers are not limiting. Also, though not shown in FIG. 13, the devices, equipment and means provided in the relay unit 3 in FIG. 1 and the like such as the gas-liquid separator 14, the expansion device 16 and the like are assumed to be mounted.

FIG. 14 is a view illustrating the connection of the valve blocks 350. As described above, the valve blocks 350 are connected so as to branch into the number of the indoor units 2. Then, each main pipe is connected. Through holes in each main pipe on the both ends are capped with the caps 318 and 319 if it is not to be connected to the outside pipeline, for example. Also, after the valve block 350 is connected, each valve block 350 is fixed by screwing or the like to a connecting plate 500 so as to form the valve block unit 300. As a result, each connected valve block 350 is contained in a housing 600 by preventing removal by a pressure of the heat medium passing through the main pipe and the like of the valve block unit 300.

FIG. 15 is a diagram illustrating an outline of the structure of the housing 600 that contains the relay unit 3. The housing 600 of the relay unit 3 is constituted by combining sheet metals 600 a and 600 b. Here, the relay unit 3 is fixed to the sheet metal 600 a and cannot be removed therefrom. On the other hand, the sheet metal 600 b is usually screwed into the sheet metal 600 a and can be slid in a direction of an arrow indicated in FIG. 15 by removing the screw. Thus, by sliding and opening/closing the sheet metal 600 b in the direction of the side face, the relay unit 3 in the housing 600 can be exposed. By forming the housing 600 in the structure that can be slidably opened/closed the sheet metal 600 b, even if the relay unit 3 is installed in a space small in the height direction such as in the attic, for example, the housing can be removed easily by sliding the sheet metal 600 b in the direction other than the height direction. In FIG. 15, the front face, the upper face, and the right side face can be removed, and maintenance works such as component replacement, maintenance and the like of the relay unit 3 can be performed through these faces. The number of faces that can be slidably opened/closed is not particularly limited, here.

Also, the valve body rotating means 310, 309, and 311 of the heat medium delivery device 21, the heat medium flow direction switching devices 22 and 23, and the heat medium flow control device 24 are concentrated so as to be oriented to one direction so that the means can be replaced through the side face of the housing 600 of the relay unit 3. In the relay unit 3 of this embodiment, as shown in FIG. 13 and the like, at least the valve body rotating means 311, 310, and 309 and the actuator (driving device) of the heat medium delivery device 21 are concentrated so as to be oriented to the front, which is the direction in which the sheet metal 600 b is slid.

Here, as shown in FIGS. 4 and 5, the valve body rotating means 311, 310, and 309 are screwed into the side face of the valve block 350. For example, if the valve body rotating means 311, 310 or 309 or the like fails and is subjected to repair or replacement of a component, a worker or the like, for example, can put the head and hands into the space in the attic and remove the screw and the valve body rotating means 311, 310 and 309 from the relay unit 3. Also, mounting of the means and device relating to repair and component replacement on the relay unit 3 can be also performed in the same way. As described above, in the relay unit 3, by concentrating the means which is likely to require maintenance such as an actuator on the one face side (one side face side in this embodiment), component replacement and the like can be facilitated, and maintenance performance can be drastically improved.

FIG. 16 is a diagram illustrating an arrangement relationship between the valve block unit 300 and the heat medium heat exchanger 15. As described above, in the relay unit 3 in this embodiment, the valve blocks 350 are connected so as to form the valve block unit 300 so as to promote thinning. Here, as shown in FIGS. 4 a, 5 and the like, on the return side to which the heat medium flows from the indoor unit, the heat medium flow direction switching device 23 and the return main pipes 305 and 306 are disposed. Also, on the outgoing side from which the heat medium flows to the indoor unit 2, the heat medium flow direction switching device 22 and the outgoing main pipes 307 and 308 are disposed. On the outgoing side, the heat medium flow control device 24 is further disposed. As described above, since the devices and pipelines are provided on the outgoing side and the return side, respectively, by generating a given distance between the first branch pipe 301 and the second branch pipe 302, a space is created.

Though not particularly illustrated in the above-described embodiment, in this embodiment, the heat medium heat exchanger 15 is constituted by a planar heat exchanger such as a micro-channel heat exchanger or the like, for example. Here, the micro-channel heat exchanger is a heat exchanger having a porous flat pipe, for example, and can efficiently exchange heat since its heat transfer area per volume (heat transfer surface density) is large.

Then, the heat medium heat exchanger 15 a is inserted into and arranged in a space generated between the first branch pipe 301 and the second branch pipe 302. Also, the heat medium heat exchanger 15 b is inserted into and arranged in a space generated at a lower part of the return branch pipe 302. Thus, when seen from the side face, as shown in FIG. 16, the outgoing branch pipe 301, the heat medium heat exchanger 15 a, the return branch pipe 302, and the heat medium heat exchanger 15 b are arranged in this order from the upper side. In the case of the above-described cooling-main operation, for example, the h heat medium heat exchanger 15 a works as a condenser and heats the heat medium, while the heat medium heat exchanger 15 b works as an evaporator and cools the heat medium. Thus, by overlapping the heat medium heat exchanger 15 a and the heat medium heat exchanger 15 b with each other, they thermally interfere with each other, which results in drastic performance deterioration. Thus, while overlapping of the heat medium heat exchanger 15 a and the heat medium heat exchanger 15 b is avoided, the space generated by the outgoing branch pipe 301 and the return branch pipe 302 is effectively used for arrangement.

Also, in FIG. 16, the heat medium heat exchanger 15 a is arranged above the heat medium heat exchanger 15 b. Since the heat medium heat exchanger 15 b works as an evaporator in the case of the cooling-main operation or the like, the temperature of the heat medium heat exchanger 15 b becomes lower than the temperature of the ambient air and condensation might occur. The condensation water drops to the lower part of the relay unit 3 and is collected in a drain pan (not shown) and is emitted from the relay unit 3, but since the heat medium heat exchanger 15 b is located on the lower side, the condensation water does not drop to the other devices and the like. Also, if the heat medium heat exchanger 15 a works as a condenser, since it warms the ambient air, rising air is generated but since the heat medium heat exchanger 15 a is located above the heat medium heat exchanger 15 b, performance of the heat medium heat exchanger 15 b as an evaporator is not lowered. From the above reasons, it is preferable that the heat medium heat exchanger 15 a is installed on the upper side and the heat medium heat exchanger 15 b on the lower side from the viewpoint of performances.

As described above, according to the relay unit 3 of Embodiment 2, by connecting the valve blocks 350 so as to form the valve block unit 300, the devices and pipelines that branch the heat medium to each indoor unit 2 and merge it can be integrated and simplified, and by further devising the pipeline positions and the like, the relay unit 3 can be thinned. Also, since the heat medium heat exchanger 15, which is a planar heat exchanger such as a micro-channel type heat exchanger or the like, is inserted into and arranged in the space generated by the outgoing branch pipe 301 and the return branch pipe 302, an unnecessary space is not created in the housing 600 but the space can be effectively used, and thinning of the relay unit 3 can be further promoted. Thus, even if the relay unit 3 is installed in an environment with harsh restrictions to one direction (height direction in the case of a space in the attic) such as a space in the attic, the device and means of the relay unit 3 can be efficiently contained in the housing 600 by effectively use the space. And the capacity of the housing 600 can be reduced, and contribution can be further made to thinning of the relay unit 3.

Also, by concentrating the means with high probability of maintenance such as an actuator on one of the faces of the relay unit 3, the maintenance work such as component replacement can be performed easily, and maintenance performance can be drastically improved. At this time, since the sheet metal 600 b is formed to be slid in the side-face direction so that the housing 600 can be opened/closed, opening/closing can be performed without being obstructed by the space small in the height direction, for example, and the merit of making a thinner structure can be enjoyed.

Embodiment 3

FIG. 17 is a diagram illustrating another example of an installed form of the relay unit 3. In the above-described embodiment, the relay unit 3 is described to be installed so-called horizontally in a space with restrictions in the height direction such as a space in the attic, but the installation place of the relay unit 3 is not limited. For example, as shown in FIG. 17, if the heat medium inverter is to be installed in a room where few people come in and out, the relay unit may be installed vertically so as to become long in the height direction. The advantage of making a thinner structure can be also exerted in the vertical installation.

Here, in the case of vertical installation, since the relay unit is hidden in the wall in many cases, it has a structure that the sheet metal 600 c can be taken out from the front side unlike the horizontal installation type. In the valve block unit 300, the valve body rotating means 310, 309, and 311 are oriented to the front shown in FIG. 17 and arranged so that the valve body rotating means 310, 309, and 311 can be replaced easily. Also, since the heat medium delivery device 21 cannot suck the heat medium by itself, the heat medium delivery device is installed close to the bottom part of the relay unit 3 so that the suction side of the heat medium delivery device 21 is naturally filled with the heat medium in the structure. The bottom face of the housing 600 should be constructed so that the heat medium can be temporarily held and the heat medium can be emitted in preparation for condensation water or accidental leakage of the heat medium. For that purpose, the bottom face has the same structure as that of the so-called drain pan. Also, in the case of the vertical installation, since it is used by being embedded in the wall in many cases, the branch pipes 301 and 302 to each indoor unit come out of the upper face, the side face, and the rear face in the structure.

Embodiment 4

FIG. 18 is a longitudinal sectional view illustrating a sectional configuration of a valve block 351 constituting a valve block unit 300 a according to Embodiment 4 of the present invention in a simplified manner. On the basis of FIG. 18, the configuration of the valve block 351 will be described along with the flow of the heat medium. In Embodiment 2, a difference from Embodiment 1 will be mainly described, and the same reference numerals are given to the same components as those in Embodiment 1 and the description will be omitted.

In Embodiment 1, the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23 switch channels by the separate valve bodies (the valve body 304 a and the valve body 304 b) and the separate valve body rotating means (valve body rotating means 309 and the valve body rotating means 310). By means of the functions of the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23, these operations are synchronized. That is, during the cooling, the heat medium flow direction switching device 22 directs the valve to the cooling direction and the heat medium flow direction switching device 23 also directs the valve to the cooling direction (See the broken-line arrow in FIG. 5). Also, during the heating, the heat medium flow direction switching device 22 directs the valve to the heating direction and the heat medium flow direction switching device 23 also directs the valve to the heating direction (See the solid-line arrow in FIG. 5).

Therefore, the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23 can be handled by one valve body rotating means and one valve body. As shown in FIG. 18, the valve block 351 is configured so that the cooling outward-flow main pipe 307 and the cooling return flow main pipe 305 as well as the heating outward-flow main pipe 308 and the heating return-flow main pipe 306 are disposed horizontally side by side, respectively. Also, in the valve block, 351, the heat medium flow direction switching device 25 that functions similarly to the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23 is disposed. That is, the heat medium flow direction switching device 25 shares the function of the heat medium flow direction switching device 22 and the heat medium flow direction switching device 23.

That is, the heat medium flow direction switching device 25 selectively switches the cooling outward-flow main pipe 307 and the heating outward-flow main pipe 308 and also selectively switches the cooling return-flow main pipe 305 and the heating return-flow main pipe 306. This heat medium flow direction switching device 25 is constituted by the valve body rotating means 405, the valve body 407, and the valve rod 409 that connects them. The valve body rotating means 405 is to rotate the valve body 407 around the rotary shaft, not shown. The rotation of the valve body rotating means 405 is transmitted to the valve body 407 via the valve rod 409. In FIG. 18, the example in which the heat medium flow control device 24 is disposed in the valve block 351 is illustrated, but this heat medium flow control device 24 is not indispensable or may be disposed on the branch pipe 302 side.

FIG. 19 is an explanatory diagram for explaining the valve body 407. On the basis of FIG. 19, the valve body 407 will be described in detail. FIG. 19 a is a perspective view of the valve body 407, FIG. 19 b is a plan view of the valve body 407, FIG. 19 c is a front view of the valve body 407 (side view seen from the side of an opening portion formed surface), FIG. 19 d is a left sectional view of the valve body 407, and FIG. 19 e is a bottom view of the valve body 407, respectively. In FIG. 19, the valve rod 409 is also illustrated. In FIG. 19, the longitudinal direction of the valve body 407 is illustrated vertically, but in actuality, the valve body 407 is arranged so that the longitudinal direction thereof is laid horizontally as shown in FIG. 18.

The valve body 407 is formed in an elongated columnar shape. In this valve body 407, an opening portion 407 a having a long hole shape (a shape when the opening portion 407 a is seen on a front view) along the longitudinal direction of the valve body 407, an opening portion 407 b having an oval shape (a shape when the opening portion 407 b is seen on a front view), and an opening portion 407 c communicating with the opening portion 407 b are formed. The opening portion 407 c is formed in the bottom face of the valve body 407. In order to have the opening portion 407 b and the opening portion 407 c communicate with each other, the inside of the valve body 407 is made hollow.

That is, in a state in which the opening portion 407 b of the valve body 407 is oriented downward (lower side in the state arranged as in FIG. 18), the first branch pipe 301 communicates with the cooling outward-flow main pipe 307 via the opening portion 407 c. In the state in which the opening portion 407 b is oriented to the cooling outward-flow main pipe 307 side, the heat medium passes through the opening portion 407 b and the opening portion 407 c, and the heat medium is fed into the indoor unit 2 (the broken-line arrow in FIG. 18). On the other hand, in a state in which the opening portion 407 b of the valve body 407 is oriented upward (upper side in the state arranged as in FIG. 18), the first branch pipe 301 communicates with the heating outward-flow main pipe 308 via the opening portion 407 c. In the state in which the opening portion 407 b is oriented to the heating outward-flow main pipe 308 side, the heat medium passes through the opening portion 407 b and the opening portion 407 c, and the heat medium is fed into the indoor unit 2 (the broken-line arrow in FIG. 18).

Similarly, in a state in which the opening portion 407 a of the valve body 407 is oriented downward (lower side in the state arranged as in FIG. 18), the second branch pipe 302 communicates with the cooling return-flow main pipe 305. In the state in which the opening portion 407 a is oriented to the cooling return-flow main pipe 305 side, the heat medium from the first branch pipe 301 flows into the cooling return-flow main pipe 305 through the opening portion 407 a (the broken-line arrow shown in FIG. 18). On the other hand, in a state in which the opening portion 407 a of the valve body 407 is oriented upward (upper side in the state arranged as in FIG. 18), the second branch pipe 302 communicates with the heating return-flow main pipe 306. In the state in which the opening portion 407 a is oriented to the heating return-flow main pipe 306 side, the heat medium from the first branch pipe 301 flows into the heating return-flow main pipe 306 through the opening portion 407 a (the broken-line arrow shown in FIG. 18).

By employing the above structure, the number of installed valve body rotating means can be reduced from 2 to 1. Thus, a cost can be reduced for the reduction. Also, since the heat medium flow direction switching devices are shared in each set, further size reduction is realized. Also, since the number of valve body rotating means is reduced, power consumption (current value) can be also reduced.

FIG. 20 is a perspective view illustrating the structure of the valve block unit 300 a in detail. FIGS. 21 and 22 are explanatory diagrams for explaining the connection of the valve block 351. On the basis of FIGS. 20 to 22, the valve block 351 will be described in detail. FIG. 21 a is a side view of the valve block 351, and FIG. 21 b is a C-C sectional view of FIG. 21 a in a state in which the valve block 351 is to be connected, respectively. Also, FIG. 22 is a perspective view illustrating a state in which the valve block 351 is to be connected.

The valve block unit 300 a shown in FIG. 20 is constituted by connecting the four valve blocks 351 (the valve block 351 a to the valve block 351 d) and connected to four indoor units 2 similarly to the valve block unit 300 according to Embodiment 1. The valve block 351 has the heat medium flow direction switching device 22, the heat medium flow direction switching device 23, and the heat medium flow control device 24, which cover one branch altogether. That is, the valve block unit 300 a according to Embodiment 2 branches into four parts.

The cooling outward-flow main pipe 307 (illustrated as the cooling outward-flow main pipe 307 a, the cooling outward-flow main pipe 307 b, and the cooling outward-flow main pipe 307 c from the right side in the figure), the heating outward-flow main pipe 308 (illustrated as the heating outward-flow main pipe 308 a, the heating outward-flow main pipe 308 b, and the heating outward-flow main pipe 308 c from the right side in the figure), the cooling return-flow main pipe 305 (illustrated as the cooling return-flow main pipe 305 a, the cooling return-flow main pipe 305 b, and the cooling return-flow main pipe 305 c from the right side in the figure), and the heating return-flow main pipe 306 (illustrated as the heating return-flow main pipe 306 a, the heating return-flow main pipe 306 b, and the heating return-flow main pipe 306 c from the right side in the figure) of each valve block 351 are connected, respectively, and form the main pipe (pipeline 5). It is needless to say that the valve block 351 d on the left side in the figure also has each main pipe.

One end of each main pipe (the cooling outward-flow main pipe 307, the heating outward-flow main pipe 308, the cooling return-flow main pipe 305, and the heating return-flow main pipe 306) is formed into a female shape and the other end is formed into a male shape capable of connecting to the female-shaped end so that the valve blocks 351 can be connected. And on the cooling outward-flow main pipe 307 a and the heating outward-flow main pipe 308 a of the valve block 351 a located at one of the both ends of the valve block unit 300 a, the caps 318 that cap them are disposed. On the other hand, on the cooling return-flow main pipe 305 d and the heating return-flow main pipe 306 d of the valve block 351 d located at the other of the both ends of the valve block unit 300 a, the caps 319 that cap them are disposed. The heating return-flow main pipe 306 a is connected to the suction side of the heating-side pump (first heat medium delivery device 21 a), and the cooling return main pump 305 a is connected to the suction side of the cooling-side pump (second heat medium delivery device 21 b), respectively.

By employing the above structure, as shown in FIGS. 21 and 22, the plurality of valve blocks 351 can be connected easily, and the number of branches can be flexibly changed. Also, since the valve blocks 350 are constructed so as to be easily connected, workability (productivity) of the valve block 350 is also improved, and cost reduction can be realized. In FIGS. 21 and 22, the cooling outward-flow main pipe 307 and the heating outward-flow main pipe 308 are described as an example, but the same applies to the cooling return-flow main pipe 305 and the heating return-flow main pipe 306.

The valve block unit 300 a is capable of switching the heat medium channel and also forms each main pipe by connecting the plurality of valve blocks 351. According to this valve block unit 300 a, as compared with the device in which the channel switching device and the pipeline are provided separately, the pipeline around the valve can be simplified. Therefore, the unit on which the valve block unit 300 a is mounted (the relay unit 3 similar to Embodiment 1) can be made compact.

A hole 411 shown in FIG. 22 is a sacrificed hole required for forming a channel of the valve block 351 and is capped with a lid 410. If the hole 411 is not capped, the return pipeline of each valve block 351 is connected, and thus, the pipeline is capped with the lid 410. On the lid 410, two seal means 410 a are disposed. Here, an example in which the seal means 410 a is an O-ring is illustrated. It is also known from FIG. 21 that the seal means 410 a is disposed on the lid 410 and shuts off the return pipeline for each valve block 351.

As described above, since the valve block unit 300 a according to Embodiment 2 is constituted by connecting the plurality of valve blocks 351, drastic size reduction can be realized. That is, the size reduction of the relay unit 3 on which the valve block unit 300 a is mounted can be realized. Also, since the valve block 351 can be easily connected, assembling performance is improved, and labor or time required for installation can be reduced. Moreover, since the valve block unit 300 a suppresses thermal interference of the pipelines 5, performance deterioration can be reduced. Therefore, by using the valve block unit 300 a, contribution can be made to energy saving.

If leakage of the valve block 351 is to be inspected, in a state of the valve block unit 300 in which the plurality of valve blocks 350 are connected as shown in FIGS. 4 and 20, a pressure of approximately 3 kgf/cm² is applied by using nitrogen, helium or the like so as to check if there is any leakage from the seal means 316 and 410 a and then, the valve block unit is shipped. It is needless to say that the main pipes 308 and 307, the branch pipes 301 and 302 in FIG. 20, and the main pipes 305 and 306 in FIG. 4 are capped so that they can be pressurized. By conducting a leakage test in the above valve block unit 300 state, inspection time can be reduced, and productivity can be improved. Also, by conducting an inspection in the number of branches actually used in the product, the quality can be made stable, production time can be reduced, and cost can be reduced. That is because if the leakage test is conducted for each valve block 350, for example, the leakage test is needed even after they are assembled into the valve block unit 300, which means that the leakage test is conducted twice, which is wasteful.

Embodiment 5

In the above-described embodiments, the example in which the valve block unit 300 is mounted on the relay unit 3 is described, but a device in which the valve block unit 300 is used is not limited to the relay unit 3. For example, the valve block unit 300 can be also used for the other three-way valves and flow controllers in the air conditioning apparatus. Also, the fluid to be passed through the valve block unit 300 is not limited to water and the like, and other fluids such as a refrigerant can be made to pass.

Here, if the valve block unit 300 is applied to a refrigerant used in an air conditioning apparatus in general, since it is difficult to apply a plastic material to the body of the valve block 350 from the viewpoint of a design pressure, brass, aluminum or the like is used. Also, if the type of the medium is changed, considering swelling or deterioration, the seal means 316 and the like need to be selected so as to be suitable for the fluid. It is needless to say that the body material of the valve block 350 needs to be selected considering corrosion or the like.

Also, in the above-described embodiments, the example in which the heat medium heated in the heat medium heat exchanger 15 a is passed through the main pipes 306 and 308, while the heat medium cooled in the heat medium heat exchanger 15 b is passed through the main pipes 305 and 307 is described, but that example is not limiting. There can be various forms such that the heat media at different temperatures according to cooling (heating) are made to pass through the both main pipes and the like. Also, as for the above-described valve block unit 300, not only in the air conditioning apparatus, but usual water (cold water) is made to pass through the cooling outward-flow main pipe 307 and hot water from a boiler is made to pass through the heating outward-flow main pipe 308, for example, the position of the valve body 304 a of the heat medium flow direction switching device 22 is adjusted, and hot water and cold water are mixed. As a result, the temperature of the hot water coming out of the branch pipe 301 can be freely controlled and can be also used for creating hot water for bath or shower.

REFERENCE SIGNS LIST

1 outdoor unit, 2 indoor unit, 2 a indoor unit, 2 b indoor unit, 2 c indoor unit, 2 d indoor unit, 3 relay unit, 4 refrigerant pipeline, 4 a connection pipeline, 4 b, connection pipeline, 5 pipeline, 5 a, pipeline, 5 b pipeline, 10 compressor, 11 four-way valve, 12 heat-source-side heat exchanger, 13 a check valve, 13 b check valve, 13 c check valve, 13 d check valve, 14 gas-liquid separator, 15 heat medium heat exchanger, 15 a first heat medium heat exchanger, 15 b second heat medium heat exchanger, 16 expansion device, 16 a expansion device, 16 b expansion device, 16 c expansion device, 16 d expansion device, 16 e expansion device, 17 accumulator, 21 heat medium delivery device, 21 a first heat medium delivery device, 21 b second heat medium delivery device, 22 heat medium flow direction switching device, 22 a heat medium flow direction switching device, 22 b heat medium flow direction switching device, 22 c heat medium flow direction switching device, 22 d heat medium flow direction switching device, 23 heat medium flow direction switching device, 23 a heat medium flow direction switching device, 23 b heat medium flow direction switching device, 23 c heat medium flow direction switching device, 23 d heat medium flow direction switching device, 24 heat medium flow control device, 24 a heat medium flow control device, 24 b heat medium flow control device, 24 c heat medium flow control device, 24 d heat medium flow control device, 25 heat medium flow direction switching device, 26 use-side heat exchanger, 26 a use-side heat exchanger, 26 b use-side heat exchanger, 26 c use-side heat exchanger, 26 d use-side heat exchanger, 31 first heat medium temperature detecting means, 31 a first heat medium temperature detecting means, 31 b first heat medium temperature detecting means, 32 second heat medium temperature detecting means, 32 a second heat medium temperature detecting means, 32 b second heat medium temperature detecting means, 33 third heat medium temperature detecting means, 33 a third heat medium temperature detecting means, 33 b third heat medium temperature detecting means, 33 c third heat medium temperature detecting means, 33 d third heat medium temperature detecting means, 34 fourth heat medium temperature detecting means, 34 a fourth heat medium temperature detecting means, 34 b fourth heat medium temperature detecting means, 34 c fourth heat medium temperature detecting means, 34 d fourth heat medium temperature detecting means, 35 first refrigerant temperature detecting means, 36 refrigerant pressure detecting means, 37 second refrigerant temperature detecting means, 38 third refrigerant temperature detecting means, 100 air conditioning apparatus, 300 valve block unit, 300 a valve block unit, 301 first branch pipe, 302 second branch pipe, 303 valve body, 303 a opening portion, 303 b channel, 304 valve body, 304 a valve body, 304 aa opening portion, 304 ab channel, 304 b valve body, 305 cooling return-flow main pipe, 305 a cooling return-flow main pipe, 305 b cooling return-flow main pipe, 305 c cooling return-flow main pipe, 305 d cooling return-flow main pipe, 306 heating return-flow main pipe, 306 a heating return-flow main pipe, 306 b heating return-flow main pipe, 306 c heating return-flow main pipe, 306 d heating return-flow main pipe, 307 cooling outward-flow main pipe, 307 a cooling outward-flow main pipe, 307 b cooling outward-flow main pipe, 307 c cooling outward-flow main pipe, 307 d cooling outward-flow main pipe, 308 heating outward-flow main pipe, 308 a heating outward-flow main pipe, 308 b heating outward-flow main pipe, 308 c heating outward-flow main pipe, 308 d heating outward-flow main pipe, 309 valve body rotating means, 310 valve body rotating means, 311 valve body rotating means, 312 valve rod, 314 valve rod 316 seal means, 318 cap, 319 cap, 320 joint, 321 sacrificed hole, 350 valve block, 350 a valve black, 350 b valve block, 350 c valve block, 350 d valve block, 351 valve block, 351 a valve block, 351 b valve block, 351 c valve block, 351 d valve block, 355 slit, 405 valve body rotating means, 407 valve body, 407 a opening portion, 407 b opening portion, 407 c opening portion, 409 valve rod, 410 lid, 410 a seal means, 411 hole, 500 connecting plate, 600 housing, 600 a, 600 b, 600 c sheet metal. 

1. A relay unit connected to one or a plurality of outdoor units and a plurality of indoor units by different pipeline systems, respectively, so as to exchange heat between a refrigerant circulating through the outdoor unit and a heat medium different from the refrigerant and to circulate the heat medium through the indoor units, the relay unit comprising: a valve block unit that connects a plurality of valve blocks, each integrating at least a plurality of branch pipes connected to the indoor units, a plurality of main pipes which become channels for the heat medium relating to the heat exchange, and a heat medium flow direction switching device that switches the main pipes to communicate with the branch pipes.
 2. The relay unit of claim 1, wherein a heat medium flow control device that adjusts a flow rate of the heat medium flowing through the branch pipes is further integrated into each of the valve blocks.
 3. The relay unit of claim 1, further comprising: a plurality of heat medium heat exchangers that exchange heat between the refrigerant and the heat medium independently; and a plurality of heat medium delivery devices that pressurize the heat medium relating to the heat exchange in each of the heat medium heat exchangers, respectively.
 4. The relay unit of claim 1, wherein the plurality of valve blocks are connected and fixed by a connecting plate.
 5. The relay unit of claim 3, wherein the heat medium delivery devices and heat medium flow direction switching devices of the valve blocks are installed so as to be detachable from the same side.
 6. The relay unit of claim 3, wherein two pipes constituting each of the branch pipes and at least one of the heat medium heat exchanger that is planar are alternately arranged.
 7. The relay unit of claim 3, wherein a housing that at least accommodates the plurality of heat medium heat exchangers, the valve block unit, and the plurality of heat medium delivery devices has a structure that is slidably opened/closed.
 8. The relay unit of claim 3, wherein among the plurality of heat medium heat exchangers, a certain number of heat medium heat exchangers are used for heating the heat medium, while the remaining heat medium heat exchangers are for cooling the heat medium.
 9. An air conditioning apparatus comprising: the relay unit of claim 1; one or a plurality of outdoor units connected to the relay unit by a pipeline and in which a refrigerant is circulated; and one or a plurality of indoor units connected to the relay unit by a different system and in which the heat medium is circulated. 